An open source pipeline for design of experiments for hyperelastic models of the skin with applications to keloids.

The aim of this work is to characterize the mechanical parameters governing the in-plane behavior of human skin and, in particular, of a keloid-scar. We consider 2D hyperelastic bi-material model of a keloid and the surrounding healthy skin. The problem of finding the optimal model parameters that minimize the misfit between the model observations and the in vivo experimental measurements is solved using our in-house developed inverse solver that is based on the FEniCS finite element computational platform. The paper focuses on the model parameter sensitivity quantification with respect to the experimental measurements, such as the displacement field and reaction force measurements. The developed tools quantify the significance of different measurements on different model parameters and, in turn, give insight into a given model's ability to capture experimental measurements. Finally, an a priori estimate for the model parameter sensitivity is proposed that is independent of the actual measurements and that is defined in the whole computational domain. This estimate is primarily useful for the design of experiments, specifically, in localizing the optimal displacement field measurement sites for the maximum impact on model parameter inference.

Long-term follow-up of pallidal Deep Brain Stimulation in teenagers with refractory Tourette syndrome and comorbid psychiatric disorders: About three cases.

OBJECTIVES: Tourette syndrome (TS) is a complex neuropsychiatric disorder associated with comorbid psychiatric disorders. Peak of tic severity typically occurs in early adolescence and impacts quality of life. Since 1999, promising therapeutic effects of Deep Brain Stimulation (DBS) have been reported in tic reduction for adults with refractory TS. The aim of the study was to assess the long-term risk-benefit ratio of pallidal DBS for young patients with refractory TS and severe comorbid psychiatric disorders. METHODS: We retrospectively assessed the long-term clinical outcomes of three adolescents who underwent pallidal DBS for the treatment of refractory TS. RESULTS: The mean duration of follow-up was 52 months in our case series. We observed that motor tics decreased with posteroventral GPi DBS in all patients, without reaching a continuous significance over the long-term follow-up. Self-reported social inclusion was globally improved, despite lack of efficacy of DBS on comorbid conditions. CONCLUSIONS: These findings suggest a long-term therapeutic benefit of early DBS intervention for highly socially impaired young patients suffering from intractable TS with severe comorbid psychiatric conditions. Further studies are needed to determine the most effective targets of DBS on both tics and comorbid psychiatric profile of TS.

Effect of arginine aspartate on the exercise-induced hyperammoniemia in humans: a two periods cross-over trial.

To investigate the effect of the ingestion of arginine aspartate (AA) in the decrease of the exercise-induced accumulation of ammonia in plasma, 11 voluntary subjects took part in a cross-over study where AA effect was tested against placebo. Both treatments were randomly administered in a double-blind procedure. To ensure the subjects would be able to present reproducible exercise-testing results during repetitive sessions, they were involved before the experiment in a cycle ergometer training program during 8 weeks. This training determined a significant 14% increase (P less than 0.001) in maximal oxygen uptake (VO2 max). The treatments were administered during 10 days and the two treatments were separated by a 10 day-wash-out period. A 45 min-cycle ergometer test was performed at 80% VO2 max during the 10th day of each treatment to measure plasma ammonia (p[NH4+]) and total blood lactate (b[lact]) concentrations at rest and at the 15th, 30th and 45th min of exercise (determinations of changes from rest; delta p[NH4+] and delta b[lact]). Both concentrations were unchanged between AA and placebo at rest but a significant lesser delta p[NH4+] was found under AA at the 15th min of exercise only (P less than 0.05). On the other hand, an order effect was found for delta p[NH4+] between the two periods of randomized treatment that was interpreted as a remaining training effect. This effect was highly significant at the 30th and 45th min of exercise (P less than 0.001). It was concluded that AA effect was minor with regard to the training effect. As it was not located at the same time of exercise, AA effect would not consequently have the same functional origin (postulated increase in the peripheral clearance of ammonia) than those of training (decrease in muscle production of ammonia).

[Prevention of abscess of the abdominal wall by continuous antisepsis, combined with antibiotherapy. 4751 cases]. / Prévention des abcès de paroi par l'antisepsie continue, associée à l'antibiothérapie. 4751 observations.

The reduced incidence of wall abscesses following routine general surgery was studied in 4751 cases over the period from 1973 to 1987. The therapeutical evolution spanned over three consecutive treatment periods, each one falling into one patient group. The reference period (Group I) extended from 1973 to 1978. Starting from 1978 and up till 1984 (Group 2), systematic repeated lavage of the operative field with an iodized polyvinylpyrrolidone solution were carried out, providing thus for true continuous antisepsis (CA). Starting from 1985 (Group 3), the method of continuous antisepsis was associated with systematic prophylactic antibiotherapy (SPAB). Groups 1, 2 and 3 included 2051, 1955 and 745 cases, respectively, and presented progressively decreasing rates of abscess formation (4%, 2.5%, 1.7%, respectively). In order to better assess these results, an in-depth analysis was carried out on two types of surgical operations, i.e., appendicitis and gynecological surgery, based on Altemeier's classification. The rate of abscess formation was lowered. This result is particularly interesting from the point of view of gynecological surgery, inasmuch as a relative increase in the frequency of the more esthetic horizontal incisions is being concurrently noted.